For food activists like Dave Murphy, founder of Food Democracy Now, the news that Cheerios changed its recipe and will no longer contain any genetically modified ingredients couldn't have come at a more opportune time.

"It's a really big move for a company like General Mills," Murphy said. "It's a huge victory for consumers."

General Mills announced the change to America's best-known breakfast cereal this month, just as the political battle over genetically modified foods heats up on the national stage.

The titans of the food industry, General Mills included, have long and successfully opposed efforts in Congress to require mandatory labeling of genetically altered foods.

But instead of letting those proposals die quietly, the Grocery Manufacturers Association is moving assertively to push industry-authored legislation that would deem all GMO labeling voluntary. Such legislation would also specifically preempt "any state labeling laws that are not identical to the federal program," according to a memo detailing the industry's battle that surfaced this week on Politico.

The effort to thwart the states is regarded as a hedge against a vocal consumer movement that is making inroads at the state level.

Until now, the fiercest confrontations over GMOs have taken place outside Washington. Maine and Connecticut passed labeling laws last year. Proposals to require labeling of genetically altered foods are under consideration in 26 states. The New Hampshire legislature is expected to vote next week on a labeling bill there, and the Vermont Senate soon after.

The food industry spent almost $70 million to defeat ballot initiatives in California and Washington state; Murphy said his organization is working to put initiatives on the November ballot in Colorado and Oregon.

An Easy Change

About 90 percent of commodity crops used in the nation's food supply, including soybeans, sugar beets, and feed corn, are genetically engineered. They are known as genetically modified organisms, or GMOs. The food industry resists labeling them out of concern that naming the presence of GMOs creates fear over food safety while it informs.

"It could be tantamount to putting a skull and crossbones on the labels," said an industry adviser in Washington who is familiar with the industry's new political strategy. "They are concerned about misleading consumers in every direction."

So why would General Mills, which is opposed to mandatory labeling, decide to purge Cheerios of GMOs now? For starters, it wasn't all that hard. There are no GMO oats, the primary ingredient in Cheerios. All General Mills had to do was switch to non-GMO sources of the small amount of cornstarch and sugar added to the cereal.

The change affects only the original Cheerios and not spinoff varieties like Honey Nut Cheerios.

"It's not much of a change at all," wrote Tom Forsythe, a General Mills spokesman in a posting on the company website. He added: "But it's not about safety. And it was never about pressure . . . We did it because we think consumers might embrace it."

"The Consumer Is King"

That's likely to be the case. While the Food and Drug Administration has deemed GMOs safe for human consumption, 9 in 10 Americans say they support the labeling of modified foods.

The Cheerios announcement is just the latest sign of a marketing trend aimed at capitalizing on consumer distrust of GMOs. Last spring, Whole Foods Market announced it will require all genetically altered products sold in its U.S. and Canadian stores to be labeled by 2018. (Trader Joe's said it eliminated GMO from products carrying the Trader Joe's label more than a decade ago.)

Chipotle Mexican Grill said it is working to eliminate genetically altered food from its menu, and Ben and Jerry's, which campaigned in support of the Washington state initiative, has announced plans to begin producing ice cream that is GMO-free by next year.

Still, the change in Cheerios is the first time an ordinary American product has dropped GMOs. The cereal is not a niche-market product, and General Mills' customer base is hardly the narrow slice of upscale patrons who shop at Whole Foods.

"It's a sign of the power of the growing grassroots movement," said Murphy, the food activist. "And a reminder that in America, the consumer is king."